Siemens SIMATIC ET 200AL, System Manual

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OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
Communication
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Function Manual, 05/2021, A5E03735815-AJ
Example
A client transmits incorrect authentication data (for example, incorrect password) when a
connection is established. The new state of the "ActivationFailed" session is entered with the
corresponding session ID in the diagnostic buffer.
Subscription states and state transitions
① Client connects to server, login with correct authentication data (correct credentials).
② Client closes connection correctly.
③ Client no longer sends messages; session ends with timeout.
④ Client connects to server, login with incorrect authentication data.
Figure 9-53 Session states and state transitions
9.3.7.4 Check for security events
If the CPU diagnostics detects a security event during the OPC UA communication, it can
enter it in the diagnostic buffer.
Requirements
• S7-1500 CPUs as of firmware version 2.8
• The "Check for security events" option is activated (properties of the CPU > OPC UA >
Server > Diagnostics).
Security events detected in diagnostics
S7-1500 CPUs perform diagnostics on the following OPC UA relevant security events:
•
Client-certificate is invalid (for example, syntactically or semantically incorrect, incorrect
signature, current date is not in the validity period)
• User name/password login failed (deactivated or incorrect data)
• Client wants to use a specific security policy or a specific message security mode; the
server does not support the security policy or the requested security mode.
• Client does not establish connection according to specification (OPC UA Spec) (for
example, unexpected SecureChannelID/SessionID/client Nonce)